RFID (radio frequency identification) tags are known for many applications. As explained in US 2009209904, conventional RFID tag systems include an RFID tag that transmits data for reception by an RFID reader (also referred to as an interrogater). In a typical RFID system, individual objects (e.g., store merchandise) are equipped with a relatively small tag that contains a transponder. The transponder has a memory chip that is given a unique electronic product code. The RFID reader emits a signal activating the transponder within the tag through the use of a communication protocol. Accordingly, the RFID reader is capable of reading and writing data to the tag. Additionally, the RFID tag reader processes the data according to the RFID tag system application. Currently, there are passive and active type RFID tags. The passive type RFID tag does not contain an internal power source, but is powered by radio frequency signals received from the RFID reader. Alternatively, the active type RFID tag contains an internal power source that enables the active type RFID tag to possess greater transmission ranges and memory capacity. The use of a passive versus an active tag is dependent upon the particular application. Accordingly, RFID tag systems have found use in a variety of applications. RFID tag system applications include animal identification, tracking items in transit, identifying drugs in hospitals or identifying lab samples such as blood.
Various different antenna configurations are known for such RFID tags. In one example a patch antenna is composed of either a thin flexible metal film such as aluminium or material that is printed using doped inks or other flexible and highly conductive materials such as conductive polymers. The antenna may be printed on the external surface of the tag in a pattern to cover a given area of the tag. The larger the area of the antenna, usually the better is the radio reception or transmission.